[9fans] adaptec 1542 -> kernel panic on boot

[Steve Simon <nospam@nospam.org>]

Hi,

I tried to add an Adaptec 1542B to a pc I hope to
use as a cpu server (for DAT and CDROM support)
and I get a panic (This is a dual Pentium Pro machine,
though I still have *nomp=1).

I am booting at present using just the current
installation floppy - but I guess it must have an
aha1542 driver as its doing somthing!

Without the scsi0=aha1542 port=0x330 in plan9.ini
the machine boots fine.

The error I get is:
panic: what ? up is zero pc 0x801a413d
ktrace /kernel/path 80106720 800005c50

I cannot see this error in ther kernel though there is
somthing similar in trap.c - maybe the error message
is getting overwritten by somthing else?

The card set for its default configuration (apart from
the BIOS and floppy being disabled).

Looking at the source (below) I wonder if the interrupt structure
has changed a bit since this code was written and the kernel
is more strict about stray interrupts than it used to be?

This is purely a guess. anyone any other / more concrete ideas?

-Steve

sdmylex.c:
/*
  * Get the id, DMA and IRQ info from the board. This will
  * cause an interrupt which will hopefully not cause any
  * trouble because the interrupt number isn't known yet.
  * This is necessary as the DMA won't be set up if the
  * board has the BIOS disabled.
  *
  * If the IRQ is already known, this must be a 32-bit PCI
  * or EISA card, in which case the returned DMA and IRQ can
  * be ignored.
  */